Electrochemical double layer capacitors (EDLCs) have been considered as a promising solution for applications requiring high power and high energy densities. The unique properties of carbon nanotubes (CNTs) such as high electrical conductivity, electrochemical, mechanical and chemical stability, high surface area and low mass density, make them proper candidates for EDLC electrodes. Vertically aligned multi-walled CNT arrays (VACNTs) have been considered for use in EDLCs due to their facile synthesis and the ability to control the ion-accessible surface. Among the several methods for VACNT production, chemical vapor deposition (CVD) has emerged as a practical and reliable method, offering versatility in terms of controlling CNT characteristics with relatively low temperature requirements (<1000 �C); however, technological advances are limited by the lack of continuous and scalable synthesis methods. Three main factors limit continuous manufacturing of nanomaterials: substrate size determined by reactor geometry, requirements of complex catalytic substrate preparation, and high operating temperatures that are incompatible with traditional current collectors (e.g., Al foil).In this work, we present a scalable roll-to-roll process for synthesizing forests of VACNTs on inexpensive Al foil ribbons, which are continuously drawn through a CVD reactor operating at ambient pressure and a relatively low growth temperature (600 �C). EDLC electrodes comprising VACNT forests synthesized in continuous and stationary CVD processes are directly assembled into supercapacitor cells, which yield high power densities (1270 W/kg) and energy densities (11.5 Wh/kg). These devices exhibit very low internal series resistance due to favorable contact with the current collector and excellent cycle stability with no loss in performance over multiple thousands of cycles.

Roll-to-roll synthesis of vertically aligned carbon nanotube electrodes for electrical double layer capacitors

248th National Meeting (2014)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.